Well that guy is known on here for boasting about himself and his belief. He's had to use several accounts on here because of how many time he's been banned for his posting behavior. Just because it's a page on a website does not mean the information is valid.

Have to disappoint you, what 'that guy' has written is absolutely correct. It's simple physics. And there isn't really anything new here. Those who worked with telescopes knew for ages that f/stop means nothing in light gathering, the lens (or mirror) collects light with its aperture:F-ratio myth

The f-stop determines the brightness, but you need to integrate over the area to get the total light, collected by the lens, and that's exactly what determines the photon noise part of S/N ratio.